It is why the embassy cannot decide this, it is up to the tax office in january to decide after they see the passport. Only the tax office can define this.
Yes, but the basic is the difinition in the tax law. All about laws are about definitions, nothing else. If it was not fot this definistion, the immigration would have an impossible job!
You will never understand this issue and the connection in the tax when you are a resident! Thailand has many laws, but only one define resident, it has nothing to do with kind of visa.
The tax law is superior to any other law. PR visas just another visa category, the PRvisa act only tell you how to obtain and knep this visa. It does not define anything else in the country. The tax law tell even the PR visa holders when they are a taxable person! Not the other way!